Well, it seems as the new hyundai's, at least the 1.6L alpha found in my 2001 accent, come with a returnless fuel system.

Problem is, from what i've seen, conventional turbo tuning techniques aren't gonna work well with this type of fuel system.

Is there any way, short of a Haltech etc, that lets you adjust the fuel curves safely on cars with returnless systems? Things like rrfpr, s-afc controllers (i know how u love them Red wink ), etc that dont 1)cost an arm and a leg and 2)dont require u to disassemble the entire car.

This is the one major snag i see in a turbo kit for new accents. Well, anyone got an idea?

 

It CAN be done, but it is damn hard. Some have converted the "returnless" fuel system into a normal sytem, others have just keep plugging away at the tuning till they make it work.

If I remember right SCC just did a turbo install on a newer miata that had the returnless system, and they somehow found a way to make it work...so it IS possible. I just don't remember off the top of my head how they did it.

 

I'll hafta dig that issue up...

I was thinking though (dangerous...) that a piggy-back ecu, such as the S-AFC or the split second controller cheuk mentioned a while back would be able to trim the fuel curves enough.

BTW, just what is the major SNAFU from the returnless fuel system? In other words, whats the problem with it... I know its something to do with fuel pressure, i think...

 

OK, found the miata article... Its in the april 2001 edition of Sport Compact Car.

It seems they got the required fuel by adding a restrictor pill into the stock regulator to bump fuel pressure by about 20psi. They then added a 255Liter/hour walbro fuel pump, a pressure switch to ground the car's air temp signal to get more fuel at the onset of boost, and ran the injectors static. All this got them about 35% more fuel, and was enough for 5spi of non-intercooled boost.

They added a TEC-II system when they raised boost.

Jackson Racing came up with the fuel strategy, so I think an email or phone call to them would be good when the time comes...

So therectically, i could just get bigger injectors, a fuel pump, add a restictor to the regulator (or some other way to make it bump up fuel pressure), and find a way to trick the ecu. Right...?

 

Here's a thought msd has a programable fuel pump booster The Booster will supply the electric fuel pump with increased voltage in relation to the manifold boost pressure.
Fuel Pump Booster

[ April 01, 2002, 01:30 PM: Message edited by: xtremepc ]

 

hmmm... thats a nifty lil box there...

 

It is not yet fully developed but the laptop programable ARC1-002 by Split sec maybe the best piggyback for a low boost bolt on turbo application. I currently use the ARC1-002.. non laptop... dials only and larger injectors for my Z3.

In conjunction with larger injectors, the ARC1-002 can dial down the injector duty cycle globally and with its built in MAP sensor can ramp up the duty cycle dependant on boost. With the current version you can only ramp up on down the boost. The laptop version... still waiting on final production dates... allow you to input duty cycles for different rpm / boost or absolute pressure readings.

I just sent Split Sec an email. Maybe they have a launch date.

 

Thanks cheuk! From what i've heard about the company and from you on the product, this might just be the answer...

BTW, how much was the system u have and was it overly difficult/complicated to install?

[ April 01, 2002, 10:14 PM: Message edited by: skierd ]

 

I think it is $250 or so... cheaper if you are a shop smile.gif but I think for a bolt on turbo this is worth a try. If you already have the S AFC you could always sell it if this works out better.

Also it is very simple to install. A handful of wires and a nipple for the vacuum/boost line.

[ April 02, 2002, 07:05 PM: Message edited by: Cheuk in Seoul ]

 

Not bad at all... With ignition timing control, the car may turn out alright.

although... I have been looking at the haltech and the sheer completeness of it is sooo tempting. I may be wrong, but it is about US$1500 right?